Lock for power tool

ABSTRACT

A power tool including a sliding member slidably received in the power tool and a pair of lock plates, each of the pair of lock plates including an opening, and the lock plates being configured such that the sliding member slides within the opening. First ends of each of the lock plates are pivotably attached to a support at a first side of the sliding member, and second ends of each of the lock plates being biased toward one another at an opposite side of the sliding member. A first contact portion of the lock plate contacts a first surface of the sliding member at the first side of the sliding member, and a second contact portion of the lock plate contacts a second surface of the sliding member at the opposite side of the sliding member, wherein the sliding member is secured with respect to the support.

FIELD OF THE INVENTION

The present invention generally relates to a power tool including a lockfor locking a sliding member. More particularly, the invention can beprovided as a lock for securing a sliding member that is mounted to ashoe of a saw, such as a reciprocating saw.

BACKGROUND OF THE INVENTION

A power saw, such as a reciprocating saw, can be provided with a shoethat assists in stabilizing the saw during cutting by resting against aworkpiece. The shoe can be pivotably mounted so that it can adjust to besquare against the workpiece. Moreover, the axial position of the shoerelative to a saw blade can be adjusted by sliding a post into or out ofthe receiving bore. For example, U.S. Pat. No. 6,671,969 (“US '969”),which is incorporated herein by reference, discloses such areciprocating saw in which the axial position of the shoe relative to asaw blade is adjusted in this way.

In the reciprocating saw of US '969, the post includes a plurality ofspaced apart detents. As such, the possible axial positions of the shoeare restricted by the spacing between the detents. Moreover, thereciprocating saw of US '969 uses a locking mechanism with a lever thatis rotated by the user's hand. A simpler locking mechanism that allowsfor more precise axial positioning would be beneficial.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a power tool includes asliding member slidably received in the power tool; a support; a biasingmember; and a pair of lock plates, each of the pair of lock platesincluding an opening, and the lock plates being configured such that thesliding member slides within the opening. First ends of each of the lockplates are pivotably attached to the support at a first side of thesliding member, and second ends of each of the lock plates being biasedtoward one another at an opposite side of the sliding member. Each ofthe pair of lock plates is biased by the biasing member such that afirst contact portion of the lock plate contacts a first surface of thesliding member at the first side of the sliding member, and a secondcontact portion of the lock plate contacts a second surface of thesliding member at the opposite side of the sliding member, wherein thesliding member is secured with respect to the support.

According to another aspect of the invention, a saw includes a saw bladeextending from the saw; a sliding member slidably received in the powertool; a support; a biasing member; and a pair of lock plates, each ofthe pair of lock plates including an opening, and the lock plates beingconfigured such that the sliding member slides within the opening. Firstends of each of the lock plates are pivotably attached to the support ata first side of the sliding member, and second ends of each of the lockplates being biased toward one another at an opposite side of thesliding member. Each of the pair of lock plates is biased by the biasingmember such that a first contact portion of the lock plate contacts afirst surface of the sliding member at the first side of the slidingmember, and a second contact portion of the lock plate contacts a secondsurface of the sliding member at the opposite side of the slidingmember, wherein the sliding member is secured with respect to thesupport.

According to another aspect of the invention, a saw includes a saw bladeextending from the saw; a sliding member slidably received in the powertool; a support; a biasing member; and a pair of lock plates, each ofthe pair of lock plates including an opening, and the lock plates beingconfigured such that the sliding member slides within the opening. Firstends of each of the lock plates are pivotably attached to the support ata first side of the sliding member, and second ends of each of the lockplates being biased toward one another at an opposite side of thesliding member. Each of the pair of lock plates is biased by the biasingmember such that a first contact portion of the lock plate contacts afirst surface of the sliding member at the first side of the slidingmember, wherein the sliding member is secured with respect to thesupport. A longitudinal axis of each lock plate is offset from an axisof rotation of the lock plate's pivot point

The saw can be a reciprocating saw.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects of the present invention will become moreapparent from the following description of exemplary embodiments, takenin conjunction with the accompanying drawings of which:

FIG. 1 depicts a reciprocating saw according to a first exemplaryembodiment of the invention.

FIGS. 2 and 3 depict a shoe assembly in accordance with the firstexemplary embodiment of the invention.

FIG. 4 depicts a perspective view of a lock in accordance with the firstexemplary embodiment.

FIG. 5 depicts a side view of the lock.

FIG. 6 is an enlarged view of the lock shown in FIG. 5.

FIGS. 7A and 7B show lock plates of the lock shown in FIGS. 4-6.

FIG. 8 depicts the lock in a secured position in which the slidingmember is secured to the support.

FIG. 9 depicts the lock in a position in which the sliding member isreleased with respect to the support.

FIG. 10A to 10C show a second exemplary embodiment of the invention.

FIGS. 11A to 11D show a lock release button and protrusion according toa second exemplary embodiment of the invention.

FIGS. 12A and 12B show features for adjustment of the shoe assembly withrespect to the second exemplary embodiment.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The matters defined in the description are provided to assist in acomprehensive understanding of the embodiments of the invention and aremerely exemplary. Accordingly, those of ordinary skill in the art willrecognize that various changes and modifications of the embodimentsdescribed herein can be made without departing from the scope and spiritof the invention. Also, descriptions of well-known functions andconstructions are omitted for clarity and conciseness.

FIG. 1 depicts a first exemplary embodiment of a reciprocating saw. Thereciprocating saw includes a handle assembly 10 and a motor assembly 20.The handle assembly 10 and the motor assembly 20 are depictedschematically since their details are not important for understandingthe invention. In fact, the handle assembly 10 and the motor assembly 20could be of any appropriate design, as will be recognized by thoseskilled in the art. Typically, the handle assembly 10 will include atrigger switch for actuating the tool, and possibly a trigger lock. Themotor assembly 20 includes a rotary electric motor. Either a cordset ora battery attaches to the handle assembly 10 or the motor assembly 20 toprovide power to the motor.

A saw blade 30 extends from the saw and has a reciprocating motion whichdefines a reciprocating motion axis. The reciprocating motion axis isgenerally parallel to the saw blade's longitudinal axis. In addition,the saw blade 30 may have other components of motion such as occurs inan orbital action reciprocating saw. A shoe assembly 300 rests againstthe workpiece being cut to help stabilize the saw.

With reference to FIGS. 2 and 3, the shoe assembly 300 will be describedin detail. However, the invention is not limited to use with a shoeassembly. The shoe assembly 300 comprises a shoe 310 mounted on a stem320. The shoe 310 can be pivotally mounted to the stem 320 via a rivet311. The shoe 310 assists in stabilizing the saw during cutting byresting against the workpiece. Because it is pivotally mounted, the shoe310 can adjust to be square against the workpiece. As shown in FIGS. 2and 3, a sliding member 321 of stem 320 is mounted with a sliding fit ina receiving bore formed in the front of the saw. A pin 322 is mounted ina bore formed in sliding member 321 and protrudes slightly from one sideof the sliding member 321. An axial groove matching the protrusion ofthe pin 322 from the sliding member 321 is formed in the receiving borein the saw so that the sliding member 321 cannot rotate inside of thereceiving bore. Thus, the shoe 310 will always be in the correct angularorientation relative to the saw blade 30. The sliding member is notlimited by shape and can be a post having a generally cylindrical shapeor any appropriate form such as a square bar, or a flat or stampedplate. The receiving bore can be easily adapted to fit the shape of thesliding member.

The axial position of the shoe 310 relative to the saw blade 30 can beadjusted by sliding the sliding member 321 into or out of the receivingbore in the saw. Axial adjustment of shoe 310 adjusts the depth to whichthe saw blade 30 extends through the workpiece. Axial adjustment of shoe310 also exposes different areas of the saw blade 30 to cutting in orderto extend the life of the saw blade. The sliding member of thisembodiment can be slid into and or out of the receiving bore without theuse of tools.

FIGS. 4-9 show the details of a lock 400, which secures the slidingmember 321 with respect to a support 410, in accordance with the firstexemplary embodiment.

As shown in FIG. 4, the lock 400 includes a pair of lock plates 420, abiasing member 430, a release button 440, the support 410, an upperbearing support 415 of the saw, and the sliding member 321.

The lock plates 420 can be made entirely of plastic, entirely of metal,or can include an internal metal portion (such a steel) with a plasticportion surrounding the metal portion. The plastic portion can be, forexample, glass filled nylon. The internal metal portion can be providedwithin the plastic portion by an insert molding process. The slidingmember 321 can be a metal, such as steel, or more particularly HardenSteel. However, the invention is not limited to the materials of thesestructures.

In the first exemplary embodiment, a shown in FIGS. 7A and 7B, the lockplates 420 include a plastic portion 420A and an internal metal portion420B. FIG. 7A shows the plastic portion 420A including a cam surface 446that contacts a corresponding cam surface of a protrusion 441 of arelease button 440, which is discussed below with respect to the secondexemplary embodiment. The plastic portion 420A also includes two supportposts 435 that support the biasing member 430 and a hole 445 throughwithin which a pivot pin 423 is provided. The internal metal portion420B includes a contact portion 421, 422, which is discussed below.

In this exemplary embodiment, the support 410 is separate structure thatis attached to the upper bearing support 415 of the saw. However, thesupport can be integrally formed with the upper bearing support 415, andthus the saw's body.

Each of the pair of lock plates 420 includes an opening 421 (see FIG.7B). The lock plates 420 are configured such that the sliding member 321slides within the opening 421 to adjust the axial position of the shoe300. As shown in FIG. 5, first ends 425 of each of the lock plates 420are pivotably attached to the support 410 by pivot pins 423 at a firstside of the sliding member 321. Second ends 424 of each of the lockplates are biased toward one another at an opposite side of the slidingmember 321 by the biasing member 430. The pivot pins 423 are providedbetween the support 415 and a support plate 405.

In this embodiment, the biasing member 430 is two pairs of compressionsprings attached to the support 410. However, the biasing member 430 isnot limited to the exemplary embodiment can also be, for example, asingle pair of compression springs, pairs of torsion springs or a singletorsion provided between the lock plates 420 at the first side (i.e.,the side closer to the pivot points of the lock plates 420) of thesliding member 321.

As shown in FIG. 6, the pair of lock plates 420 are biased by thebiasing member 430 such that a first contact portion 421 of the lockplate 420 contacts a first exterior surface 322 of the sliding member321, and a second contact portion 422 of the lock plate 420 contacts asecond exterior surface 323 of the sliding member 321 to secure thesliding member 321 in place.

In the exemplary embodiment shown in FIG. 6, the two contact portions421, 422 are formed at opposite interior sides of the opening 421 in thelock plate 420. Each contact portion 421, 422 is a corner portion thatis wedged within small indentations 324 provided on exterior surfaces322, 323 of the sliding member 321. A wedging action across the cornerportion 421, 422 locks the sliding member 321 in place. The invention isnot limited to surfaces 322, 323 having indentations, however. Instead,the surfaces 322, 323 can be substantially smooth or textured so that afriction force between the contact portions 421, 422 of the lock plates420 and the surfaces 322, 323 of the sliding member secures the slidingmember 321 in place. Referring to FIG. 6, the lower contact portion 422at the right prevents the sliding member 321 from moving to the left,while the upper contact portion 421 at the right prevents the slidingmember 321 from moving to the right. The lower contact portion at theleft (not labeled in FIG. 6) prevents the sliding member 321 from movingto the right, while the upper contact portion at the left (unlabeled)prevents the sliding member 321 from moving to the left.

In the exemplary embodiment, as shown in FIG. 5, a longitudinal axis Lat the center of each lock plate 420 is offset from an axis of rotationof the lock plate's pivot pin 423. This offset allows the surface ofeach lock plate 420 to be displaced away from the surface 323 of thesliding member 321. The sliding member 321 can then freely slide,allowing a user to adjust the position of the shoe 300 with respect tothe saw blade 30.

Referring to FIGS. 8 and 9, the release button 440 is provided at thefirst side (i.e., the side closer to the pivot points of the lock plates420) of the sliding member 321. The release button 440 includes aprotrusion 441 that extends between the lock plates 420. When therelease button 440 is pushed inward, the protrusion 441 is providedbetween the lock plates 421 and cam surfaces at a distal end of theprotrusion push against cam surfaces of the lock plates 421, pushing thelock plates away from one another, and overcoming a force of the biasingmember 430. This releases the sliding member 321 with respect to thesupport, as shown in FIG. 8. The protrusion 441 includes a slot 443within which at least one rib 444 (see FIGS. 4 and 5) extending from thesupport 410 slides. The at least one rib 445 and slot 444 providesupport for and prevent rotation of the release button 440.

The release button 440 also includes a release biasing member 442 thatbiases the release button 440 to a position in which the protrusion 441does not contact the lock plates 420. The release biasing member in theexemplary embodiments is a compression spring. However, the invention isnot limited in this aspect and the biasing member can be anotherstructure, such as a torsion spring.

FIGS. 10A to 10C show a second exemplary embodiment of the invention.The features of the second exemplary embodiment are the same as those ofthe first exemplary embodiment, except for the features discussed below.

In this embodiment, the structure that supports the lock plates 420 isintegrally formed as a part of the upper bearing support 615. Moreover,a large support plate 605 is used instead of the smaller support plate405 shown in FIG. 4. The support plate 605 is attached to the upperbearing support 615 by screws.

As shown in FIG. 10C (with plate 605 and part of the biasing member 430removed), as in the first exemplary embodiment, the lock plates 420 arebiased by the biasing member 430 to secure the contact portions 421, 422against contact surfaces of the sliding member 321. A felt seal 620 isprovided to prevent debris from entering the structures of the lock.

FIG. 11A shows a release button 640 of the second exemplary embodiment.As in the first embodiment, the release button 640 includes a protrusion641 and cam surfaces 647 that contact and push corresponding camsurfaces 446 of the lock plates 420. FIG. 11C shows the protrusion 641approaching the lock plates 420, and FIG. 11D shows the lock after thelock plates 420 have been pushed, allowing the sliding member 321 toslide freely. The release button 640 includes a contact portion 650 thatis pushed by a user to release the lock plates 420.

As in the first exemplary embodiment, a slot 643 is provided within theprotrusion for engaging at least one rib 644 extending from the upperbearing support 415, and as in the first exemplary embodiment, a releasebiasing member 642 biases the release button 640 to a position in whichthe protrusion 641 does not contact the lock plates 420. In thisexemplary embodiment, the release biasing member 642 is provided on asupport 670 and is secured between a lower one of the ribs 644 and thesupport 670. The protrusion 641 of the release button 640 also includesextensions 660, which slide on a surface of the upper bearing support615 to stabilize the release button 640.

FIGS. 12A and 12B show features for adjustment of the shoe assembly withrespect to the second exemplary embodiment. As shown in FIG. 12A,increments are indicated on the sliding member 321. These incrementscorrespond to a distance between a fixed shoe 500 and the movable shoe300. For example, the increment indicated in FIG. 12A is 1 inch and theoutside diameter of a pipe P shown in FIG. 12B is also 1 inch. As shownin FIG. 12A, by aligning the increment on the sliding member 321 with arib 700 on the saw's housing, a user can readily determine the distancebetween the fixed shoe 500 and the movable shoe 300. The distancebetween the fixed shoe 500 and the movable shoe 300 is adjusted byreleasing the sliding member 321 and changing the position of themovable shoe 300. For example, FIG. 12B shows the shoes 300, 500 of thesaw secured around the pipe P.

The invention has been described and illustrated several exemplaryembodiments. It will be appreciated, however, that the invention can beapplied otherwise, and that the dimensions, materials and othervariables may be altered to suit individual design considerationswithout departing from the spirit and scope of the present invention.

1. A power tool, comprising: a sliding member slidably received in thepower tool; a support; a biasing member; and a pair of lock plates, eachof the pair of lock plates including an opening, and the lock platesbeing configured such that the sliding member slides within the opening,first ends of each of the lock plates being pivotably attached to thesupport at a first side of the sliding member, and second ends of eachof the lock plates being biased toward one another at an opposite sideof the sliding member, each of the pair of lock plates being biased bythe biasing member such that a first contact portion of the lock platecontacts a first surface of the sliding member at the first side of thesliding member, and a second contact portion of the lock plate contactsa second surface of the sliding member at the opposite side of thesliding member, wherein the sliding member is secured with respect tothe support.
 2. The power tool according to claim 1, wherein alongitudinal axis of each lock plate is offset from an axis of rotationof the lock plate's pivot point.
 3. The power tool according to claim 1,further comprising: a shoe for bearing against a workpiece, the shoeextending from the power tool and mounted to the sliding member.
 4. Thepower tool according to claim 3, further comprising a release buttonprovided at the opposite side of the sliding member, the release buttonincluding a protrusion, wherein, when the lock button is pressed, theprotrusion extends between the lock plates and pushes the lock platesaway from one another, overcoming a force of the biasing member andreleasing the sliding member with respect to the support.
 5. The powertool according to claim 4, wherein the release button includes a releasebiasing member that biases the release button to a position in which theprotrusion does not contact the lock plates.
 6. The power tool accordingto claim 2, wherein the biasing member comprises, at least onecompression spring or at least one torsion spring.
 7. The power toolaccording to claim 6, wherein the biasing member comprises a pair ofcompression springs.
 8. The power tool according to claim 1, wherein thefirst and second surfaces of the sliding member comprises a plurality ofindentations.
 9. The power tool according to claim 1, wherein each ofthe first and second surfaces of the sliding member comprises a texturedsurface.
 10. The power tool according to claim 1, wherein each of thefirst and second contact portions comprises a corner portion.
 11. A saw,comprising: a saw blade extending from the saw; a sliding memberslidably received in the power tool; a support; a biasing member; and apair of lock plates, each of the pair of lock plates including anopening, and the lock plates being configured such that the slidingmember slides within the opening; and a shoe for bearing against aworkpiece, the shoe extending from the saw and mounted to the slidingmember, first ends of each of the lock plates being pivotably attachedto the support at a first side of the sliding member, and second ends ofeach of the lock plates being biased toward one another at an oppositeside of the sliding member, each of the pair of lock plates being biasedby the biasing member such that a first contact portion of the lockplate contacts a first surface of the sliding member at the first sideof the sliding member, and a second contact portion of the lock platecontacts a second surface of the sliding member at the opposite side ofthe sliding member, wherein the sliding member is secured with respectto the support.
 12. The saw according to claim 11, wherein the saw is areciprocating saw, and the saw blade is a saw blade having areciprocating motion.
 13. The saw according to claim 12, wherein alongitudinal axis of each lock plate is offset from an axis of rotationof the lock plate's pivot point.
 14. The saw according to claim 12,further comprising a release button provided at the opposite side of thesliding member, the release button including a protrusion, wherein, whenthe lock button is pressed, the protrusion extends between the lockplates and pushes the lock plates away from one another, overcoming aforce of the biasing member and releasing the sliding member withrespect to the support.
 15. The saw according to claim 14, wherein therelease button includes a release biasing member that biases the releasebutton to a position in which the protrusion does not contact the lockplates.
 16. The saw according to claim 12, wherein the biasing membercomprises at least one compression spring or at least one torsionspring.
 17. The saw according to claim 16, wherein the biasing membercomprises a pair of compression springs.
 18. The saw according to claim12, wherein the first and second surfaces of the sliding membercomprises a plurality of indentations.
 19. The saw according to claim12, wherein each of the first and second surfaces of the sliding membercomprises a textured surface.
 20. A power tool, comprising: a slidingmember slidably received in the power tool; a support; a biasing member;and a pair of lock plates, each of the pair of lock plates including anopening, and the lock plates being configured such that the slidingmember slides within the opening, first ends of each of the lock platesbeing pivotably attached to the support at a first side of the slidingmember, and second ends of each of the lock plates being biased towardone another at an opposite side of the sliding member, each of the pairof lock plates being biased by the biasing member such that a firstcontact portion of the lock plate contacts a first surface of thesliding member at the first side of the sliding member, wherein thesliding member is secured with respect to the support, wherein alongitudinal axis of each lock plate is offset from an axis of rotationof the lock plate's pivot point.